fix(undefined check): a) undefined check in JS 2) when 2nd para is a …

…function, only apply when extra

src/index.js

@@ -1,3 +1,5 @@
+const isUndefined = (value) => typeof value === 'undefined'
+
 const evalMatchedPatternByStatmentsType = {
   'string': (_obj, value, _args) => value,
   'number': (_obj, value, _args) => value,
@@ -6,8 +8,11 @@ const evalMatchedPatternByStatmentsType = {
   'object': (_obj, value, _args) => value,
 }
 
-const evalMatchedPattern = (obj, statements, ...args) =>
-  evalMatchedPatternByStatmentsType[typeof statements](obj, statements, ...args)
+const evalMatchedPattern = (obj, statements, ...args) => {
+  if( !isUndefined(obj) )  {
+    return evalMatchedPatternByStatmentsType[typeof statements](obj, statements, ...args);
+  }
+}
 
 const primitivePatternHandler = (exp, [pattern, statements, ...args]) => {
   if(primitiveValueEqualTest(exp, pattern)) {
@@ -57,7 +62,7 @@ const handlerByPatternType = {
   'function': (exp, [pattern, statements, ...args]) => {
     if ('unapply' in pattern.prototype) {
       const extractObj = pattern.prototype.unapply(exp);
-      if (extractObj != undefined) {
+      if ( !isUndefined(extractObj) ) {
         return evalMatchedPattern(extractObj, statements, ...args);
       }
     }
@@ -84,9 +89,9 @@ const handlerByPatternType = {
 
 const match = exp => (...pattern_clauses) => {
   for (const [pattern, statements, ...args] of pattern_clauses) {
-    const optionPrimitiveResult = handlerByPatternType[typeof pattern](exp, [pattern, statements, ...args]);
-    if (optionPrimitiveResult != undefined) {
-      return optionPrimitiveResult;
+    const optionResult = handlerByPatternType[typeof pattern](exp, [pattern, statements, ...args]);
+    if (!isUndefined(optionResult)) {
+      return optionResult;
     }
   };
   return undefined;

test/twice_class.spec.coffee

@@ -18,6 +18,7 @@ object TwiceTest extends App
 chai = require 'chai'
 matchJS = require '../lib/match-js'
 match = matchJS.match
+otherwise = matchJS.otherwise
 
 chai.expect()
 expect = chai.expect
@@ -88,3 +89,11 @@ describe 'Matching on class contructor Twice:', ->
         [Twice, (x) => x]
       )
       expect(m).to.be.equal 'Twice(6) matches value:12'
+
+  it '9 should not match Twice, but otherwise', ->
+      m = match(9)(
+        [1, 'ONE'],
+        [Twice, (x) => x],
+        [otherwise, '9 matches otherwise']
+      )
+      expect(m).to.be.equal '9 matches otherwise'

test/twice_class.spec.es5.js

@@ -16,7 +16,9 @@ object TwiceTest extends App {
 */
 
 var chai = require('chai');
-var match = require('../lib/match-js').match;
+var matchJS = require('../lib/match-js');
+var match = matchJS.match;
+var otherwise = matchJS.otherwise;
 
 chai.expect();
 var expect = chai.expect;
@@ -89,4 +91,12 @@ describe('Matching on class contructor Twice:', function() {
     );
     expect(m).to.be.equal('Twice(6) matches {value:12}');
   });
+  it('9 should not match Twice, but otherwise', function() {
+    var m = match(9)(
+      [1, 'ONE'],
+      [Twice, function(x) { return x; }],
+      [otherwise, '9 matches otherwise']
+    );
+    expect(m).to.be.equal('9 matches otherwise');
+  });
 });

test/twice_class.spec.es6.js

@@ -16,7 +16,7 @@ object TwiceTest extends App {
 */
 
 import chai from 'chai';
-import { match }from '../lib/match-js';
+import { match, otherwise }from '../lib/match-js';
 
 chai.expect();
 const expect = chai.expect;
@@ -92,4 +92,12 @@ describe('Matching on class contructor Twice:', function () {
       )
       expect(m).to.be.equal('Twice(6) matches {value:12}');
   });
+  it('9 should not match Twice, but otherwise', () => {
+      const m = match(9)(
+        [1, 'ONE'],
+        [Twice, (x) => x],
+        [otherwise, '9 matches otherwise']
+      )
+      expect(m).to.be.equal('9 matches otherwise');
+  });
 });